// SPDX-License-Identifier: GPL-2.0+
/*
 * drivers/of/property.c - Procedures for accessing and interpreting
 *			   Devicetree properties and graphs.
 *
 * Initially created by copying procedures from drivers/of/base.c. This
 * file contains the OF property as well as the OF graph interface
 * functions.
 *
 * Paul Mackerras	August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 *
 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *    {engebret|bergner}@us.ibm.com
 *
 *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
 *
 *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
 *  Grant Likely.
 */
#define pr_fmt(fmt)	"OF: " fmt

#include <seminix/of.h>
#include <seminix/string.h>
#include <seminix/of_graph.h>
#include <seminix/fwnode.h>
#include "of_private.h"

/**
 * of_property_count_elems_of_size - Count the number of elements in a property
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @elem_size:	size of the individual element
 *
 * Search for a property in a device node and count the number of elements of
 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
 * property does not exist or its length does not match a multiple of elem_size
 * and -ENODATA if the property does not have a value.
 */
int of_property_count_elems_of_size(const struct device_node *np,
                const char *propname, int elem_size)
{
    struct property *prop = of_find_property(np, propname, NULL);

    if (!prop)
        return -EINVAL;
    if (!prop->value)
        return -ENODATA;

    if (prop->length % elem_size != 0) {
        pr_err("size of %s in node %pOF is not a multiple of %d\n",
               propname, np, elem_size);
        return -EINVAL;
    }

    return prop->length / elem_size;
}

/**
 * of_find_property_value_of_size
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @min:	minimum allowed length of property value
 * @max:	maximum allowed length of property value (0 means unlimited)
 * @len:	if !=NULL, actual length is written to here
 *
 * Search for a property in a device node and valid the requested size.
 * Returns the property value on success, -EINVAL if the property does not
 *  exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data is too small or too large.
 *
 */
static void *of_find_property_value_of_size(const struct device_node *np,
            const char *propname, u32 min, u32 max, usize *len)
{
    struct property *prop = of_find_property(np, propname, NULL);

    if (!prop)
        return ERR_PTR(-EINVAL);
    if (!prop->value)
        return ERR_PTR(-ENODATA);
    if (prop->length < (int)min)
        return ERR_PTR(-EOVERFLOW);
    if (max && prop->length > (int)max)
        return ERR_PTR(-EOVERFLOW);

    if (len)
        *len = prop->length;

    return prop->value;
}

/**
 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @index:	index of the u32 in the list of values
 * @out_value:	pointer to return value, modified only if no error.
 *
 * Search for a property in a device node and read nth 32-bit value from
 * it. Returns 0 on success, -EINVAL if the property does not exist,
 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
 * The out_value is modified only if a valid u32 value can be decoded.
 */
int of_property_read_u32_index(const struct device_node *np,
                       const char *propname,
                       u32 index, u32 *out_value)
{
    const u32 *val = of_find_property_value_of_size(np, propname,
                    ((index + 1) * sizeof(*out_value)),
                    0,
                    NULL);

    if (IS_ERR(val))
        return PTR_ERR(val);

    *out_value = be32_to_cpup(((__be32 *)val) + index);
    return 0;
}

/**
 * of_property_read_u64_index - Find and read a u64 from a multi-value property.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @index:	index of the u64 in the list of values
 * @out_value:	pointer to return value, modified only if no error.
 *
 * Search for a property in a device node and read nth 64-bit value from
 * it. Returns 0 on success, -EINVAL if the property does not exist,
 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
 * The out_value is modified only if a valid u64 value can be decoded.
 */
int of_property_read_u64_index(const struct device_node *np,
                       const char *propname,
                       u32 index, u64 *out_value)
{
    const u64 *val = of_find_property_value_of_size(np, propname,
                    ((index + 1) * sizeof(*out_value)),
                    0, NULL);

    if (IS_ERR(val))
        return PTR_ERR(val);

    *out_value = be64_to_cpup(((__be64 *)val) + index);
    return 0;
}

/**
 * of_property_read_variable_u8_array - Find and read an array of u8 from a
 * property, with bounds on the minimum and maximum array size.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_values:	pointer to return value, modified only if return value is 0.
 * @sz_min:	minimum number of array elements to read
 * @sz_max:	maximum number of array elements to read, if zero there is no
 *		upper limit on the number of elements in the dts entry but only
 *		sz_min will be read.
 *
 * Search for a property in a device node and read 8-bit value(s) from
 * it. Returns number of elements read on success, -EINVAL if the property
 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
 * if the property data is smaller than sz_min or longer than sz_max.
 *
 * dts entry of array should be like:
 *	property = /bits/ 8 <0x50 0x60 0x70>;
 *
 * The out_values is modified only if a valid u8 value can be decoded.
 */
int of_property_read_variable_u8_array(const struct device_node *np,
                    const char *propname, u8 *out_values,
                    usize sz_min, usize sz_max)
{
    usize sz, count;
    const u8 *val = of_find_property_value_of_size(np, propname,
                        (sz_min * sizeof(*out_values)),
                        (sz_max * sizeof(*out_values)),
                        &sz);

    if (IS_ERR(val))
        return PTR_ERR(val);

    if (!sz_max)
        sz = sz_min;
    else
        sz /= sizeof(*out_values);

    count = sz;
    while (count--)
        *out_values++ = *val++;

    return sz;
}

/**
 * of_property_read_variable_u16_array - Find and read an array of u16 from a
 * property, with bounds on the minimum and maximum array size.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_values:	pointer to return value, modified only if return value is 0.
 * @sz_min:	minimum number of array elements to read
 * @sz_max:	maximum number of array elements to read, if zero there is no
 *		upper limit on the number of elements in the dts entry but only
 *		sz_min will be read.
 *
 * Search for a property in a device node and read 16-bit value(s) from
 * it. Returns number of elements read on success, -EINVAL if the property
 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
 * if the property data is smaller than sz_min or longer than sz_max.
 *
 * dts entry of array should be like:
 *	property = /bits/ 16 <0x5000 0x6000 0x7000>;
 *
 * The out_values is modified only if a valid u16 value can be decoded.
 */
int of_property_read_variable_u16_array(const struct device_node *np,
                    const char *propname, u16 *out_values,
                    usize sz_min, usize sz_max)
{
    usize sz, count;
    const __be16 *val = of_find_property_value_of_size(np, propname,
                        (sz_min * sizeof(*out_values)),
                        (sz_max * sizeof(*out_values)),
                        &sz);

    if (IS_ERR(val))
        return PTR_ERR(val);

    if (!sz_max)
        sz = sz_min;
    else
        sz /= sizeof(*out_values);

    count = sz;
    while (count--)
        *out_values++ = be16_to_cpup(val++);

    return sz;
}

/**
 * of_property_read_variable_u32_array - Find and read an array of 32 bit
 * integers from a property, with bounds on the minimum and maximum array size.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_values:	pointer to return value, modified only if return value is 0.
 * @sz_min:	minimum number of array elements to read
 * @sz_max:	maximum number of array elements to read, if zero there is no
 *		upper limit on the number of elements in the dts entry but only
 *		sz_min will be read.
 *
 * Search for a property in a device node and read 32-bit value(s) from
 * it. Returns number of elements read on success, -EINVAL if the property
 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
 * if the property data is smaller than sz_min or longer than sz_max.
 *
 * The out_values is modified only if a valid u32 value can be decoded.
 */
int of_property_read_variable_u32_array(const struct device_node *np,
                   const char *propname, u32 *out_values,
                   usize sz_min, usize sz_max)
{
    usize sz, count;
    const __be32 *val = of_find_property_value_of_size(np, propname,
                        (sz_min * sizeof(*out_values)),
                        (sz_max * sizeof(*out_values)),
                        &sz);

    if (IS_ERR(val))
        return PTR_ERR(val);

    if (!sz_max)
        sz = sz_min;
    else
        sz /= sizeof(*out_values);

    count = sz;
    while (count--)
        *out_values++ = be32_to_cpup(val++);

    return sz;
}

/**
 * of_property_read_u64 - Find and read a 64 bit integer from a property
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_value:	pointer to return value, modified only if return value is 0.
 *
 * Search for a property in a device node and read a 64-bit value from
 * it. Returns 0 on success, -EINVAL if the property does not exist,
 * -ENODATA if property does not have a value, and -EOVERFLOW if the
 * property data isn't large enough.
 *
 * The out_value is modified only if a valid u64 value can be decoded.
 */
int of_property_read_u64(const struct device_node *np, const char *propname,
             u64 *out_value)
{
    const __be32 *val = of_find_property_value_of_size(np, propname,
                        sizeof(*out_value),
                        0,
                        NULL);

    if (IS_ERR(val))
        return PTR_ERR(val);

    *out_value = of_read_number(val, 2);
    return 0;
}

/**
 * of_property_read_variable_u64_array - Find and read an array of 64 bit
 * integers from a property, with bounds on the minimum and maximum array size.
 *
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_values:	pointer to return value, modified only if return value is 0.
 * @sz_min:	minimum number of array elements to read
 * @sz_max:	maximum number of array elements to read, if zero there is no
 *		upper limit on the number of elements in the dts entry but only
 *		sz_min will be read.
 *
 * Search for a property in a device node and read 64-bit value(s) from
 * it. Returns number of elements read on success, -EINVAL if the property
 * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
 * if the property data is smaller than sz_min or longer than sz_max.
 *
 * The out_values is modified only if a valid u64 value can be decoded.
 */
int of_property_read_variable_u64_array(const struct device_node *np,
                   const char *propname, u64 *out_values,
                   usize sz_min, usize sz_max)
{
    usize sz, count;
    const __be32 *val = of_find_property_value_of_size(np, propname,
                        (sz_min * sizeof(*out_values)),
                        (sz_max * sizeof(*out_values)),
                        &sz);

    if (IS_ERR(val))
        return PTR_ERR(val);

    if (!sz_max)
        sz = sz_min;
    else
        sz /= sizeof(*out_values);

    count = sz;
    while (count--) {
        *out_values++ = of_read_number(val, 2);
        val += 2;
    }

    return sz;
}

/**
 * of_property_read_string - Find and read a string from a property
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_string:	pointer to null terminated return string, modified only if
 *		return value is 0.
 *
 * Search for a property in a device tree node and retrieve a null
 * terminated string value (pointer to data, not a copy). Returns 0 on
 * success, -EINVAL if the property does not exist, -ENODATA if property
 * does not have a value, and -EILSEQ if the string is not null-terminated
 * within the length of the property data.
 *
 * The out_string pointer is modified only if a valid string can be decoded.
 */
int of_property_read_string(const struct device_node *np, const char *propname,
                const char **out_string)
{
    const struct property *prop = of_find_property(np, propname, NULL);
    if (!prop)
        return -EINVAL;
    if (!prop->value)
        return -ENODATA;
    if ((int)strnlen(prop->value, prop->length) >= prop->length)
        return -EILSEQ;
    *out_string = prop->value;
    return 0;
}

/**
 * of_property_match_string() - Find string in a list and return index
 * @np: pointer to node containing string list property
 * @propname: string list property name
 * @string: pointer to string to search for in string list
 *
 * This function searches a string list property and returns the index
 * of a specific string value.
 */
int of_property_match_string(const struct device_node *np, const char *propname,
                 const char *string)
{
    const struct property *prop = of_find_property(np, propname, NULL);
    usize l;
    int i;
    const char *p, *end;

    if (!prop)
        return -EINVAL;
    if (!prop->value)
        return -ENODATA;

    p = prop->value;
    end = p + prop->length;

    for (i = 0; p < end; i++, p += l) {
        l = strnlen(p, end - p) + 1;
        if (p + l > end)
            return -EILSEQ;
        pr_debug("comparing %s with %s\n", string, p);
        if (strcmp(string, p) == 0)
            return i; /* Found it; return index */
    }
    return -ENODATA;
}

/**
 * of_property_read_string_helper() - Utility helper for parsing string properties
 * @np:		device node from which the property value is to be read.
 * @propname:	name of the property to be searched.
 * @out_strs:	output array of string pointers.
 * @sz:		number of array elements to read.
 * @skip:	Number of strings to skip over at beginning of list.
 *
 * Don't call this function directly. It is a utility helper for the
 * of_property_read_string*() family of functions.
 */
int of_property_read_string_helper(const struct device_node *np,
                   const char *propname, const char **out_strs,
                   usize sz, int skip)
{
    const struct property *prop = of_find_property(np, propname, NULL);
    int l = 0, i = 0;
    const char *p, *end;

    if (!prop)
        return -EINVAL;
    if (!prop->value)
        return -ENODATA;
    p = prop->value;
    end = p + prop->length;

    for (i = 0; p < end && (!out_strs || i < skip + (int)sz); i++, p += l) {
        l = strnlen(p, end - p) + 1;
        if (p + l > end)
            return -EILSEQ;
        if (out_strs && i >= skip)
            *out_strs++ = p;
    }
    i -= skip;
    return i <= 0 ? -ENODATA : i;
}

const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
                   u32 *pu)
{
    const void *curv = cur;

    if (!prop)
        return NULL;

    if (!cur) {
        curv = prop->value;
        goto out_val;
    }

    curv += sizeof(*cur);
    if (curv >= prop->value + prop->length)
        return NULL;

out_val:
    *pu = be32_to_cpup(curv);
    return curv;
}

const char *of_prop_next_string(struct property *prop, const char *cur)
{
    const void *curv = cur;

    if (!prop)
        return NULL;

    if (!cur)
        return prop->value;

    curv += strlen(cur) + 1;
    if (curv >= prop->value + prop->length)
        return NULL;

    return curv;
}

/**
 * of_graph_parse_endpoint() - parse common endpoint node properties
 * @node: pointer to endpoint device_node
 * @endpoint: pointer to the OF endpoint data structure
 *
 * The caller should hold a reference to @node.
 */
int of_graph_parse_endpoint(const struct device_node *node,
                struct of_endpoint *endpoint)
{
    struct device_node *port_node = of_get_parent(node);

    WARN_ONCE(!port_node, "%s(): endpoint %pOF has no parent node\n",
          __func__, node);

    memset(endpoint, 0, sizeof(*endpoint));

    endpoint->local_node = node;
    /*
     * It doesn't matter whether the two calls below succeed.
     * If they don't then the default value 0 is used.
     */
    of_property_read_u32(port_node, "reg", &endpoint->port);
    of_property_read_u32(node, "reg", &endpoint->id);

    return 0;
}

/**
 * of_graph_get_port_by_id() - get the port matching a given id
 * @parent: pointer to the parent device node
 * @id: id of the port
 *
 * Return: A 'port' node pointer with refcount incremented. The caller
 * has to use of_node_put() on it when done.
 */
struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
{
    struct device_node *node, *port;

    node = of_get_child_by_name(parent, "ports");
    if (node)
        parent = node;

    for_each_child_of_node(parent, port) {
        u32 port_id = 0;

        if (!of_node_name_eq(port, "port"))
            continue;
        of_property_read_u32(port, "reg", &port_id);
        if (id == port_id)
            break;
    }

    return port;
}

/**
 * of_graph_get_next_endpoint() - get next endpoint node
 * @parent: pointer to the parent device node
 * @prev: previous endpoint node, or NULL to get first
 *
 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
 * of the passed @prev node is decremented.
 */
struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
                    struct device_node *prev)
{
    struct device_node *endpoint;
    struct device_node *port;

    if (!parent)
        return NULL;

    /*
     * Start by locating the port node. If no previous endpoint is specified
     * search for the first port node, otherwise get the previous endpoint
     * parent port node.
     */
    if (!prev) {
        struct device_node *node;

        node = of_get_child_by_name(parent, "ports");
        if (node)
            parent = node;

        port = of_get_child_by_name(parent, "port");

        if (!port) {
            pr_err("graph: no port node found in %pOF\n", parent);
            return NULL;
        }
    } else {
        port = of_get_parent(prev);
        if (WARN_ONCE(!port, "%s(): endpoint %pOF has no parent node\n",
                  __func__, prev))
            return NULL;
    }

    while (1) {
        /*
         * Now that we have a port node, get the next endpoint by
         * getting the next child. If the previous endpoint is NULL this
         * will return the first child.
         */
        endpoint = of_get_next_child(port, prev);
        if (endpoint) {
            return endpoint;
        }

        /* No more endpoints under this port, try the next one. */
        prev = NULL;

        do {
            port = of_get_next_child(parent, port);
            if (!port)
                return NULL;
        } while (!of_node_name_eq(port, "port"));
    }
}

/**
 * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
 * @parent: pointer to the parent device node
 * @port_reg: identifier (value of reg property) of the parent port node
 * @reg: identifier (value of reg property) of the endpoint node
 *
 * Return: An 'endpoint' node pointer which is identified by reg and at the same
 * is the child of a port node identified by port_reg. reg and port_reg are
 * ignored when they are -1.
 */
struct device_node *of_graph_get_endpoint_by_regs(
    const struct device_node *parent, int port_reg, int reg)
{
    struct of_endpoint endpoint;
    struct device_node *node = NULL;

    for_each_endpoint_of_node(parent, node) {
        of_graph_parse_endpoint(node, &endpoint);
        if (((port_reg == -1) || ((int)endpoint.port == port_reg)) &&
            ((reg == -1) || ((int)endpoint.id == reg)))
            return node;
    }

    return NULL;
}

/**
 * of_graph_get_remote_endpoint() - get remote endpoint node
 * @node: pointer to a local endpoint device_node
 *
 * Return: Remote endpoint node associated with remote endpoint node linked
 *	   to @node. Use of_node_put() on it when done.
 */
struct device_node *of_graph_get_remote_endpoint(const struct device_node *node)
{
    /* Get remote endpoint node. */
    return of_parse_phandle(node, "remote-endpoint", 0);
}

/**
 * of_graph_get_port_parent() - get port's parent node
 * @node: pointer to a local endpoint device_node
 *
 * Return: device node associated with endpoint node linked
 *	   to @node. Use of_node_put() on it when done.
 */
struct device_node *of_graph_get_port_parent(struct device_node *node)
{
    unsigned int depth;

    if (!node)
        return NULL;

    /* Walk 3 levels up only if there is 'ports' node. */
    for (depth = 3; depth && node; depth--) {
        node = of_get_next_parent(node);
        if (depth == 2 && !of_node_name_eq(node, "ports"))
            break;
    }
    return node;
}

/**
 * of_graph_get_remote_port_parent() - get remote port's parent node
 * @node: pointer to a local endpoint device_node
 *
 * Return: Remote device node associated with remote endpoint node linked
 *	   to @node. Use of_node_put() on it when done.
 */
struct device_node *of_graph_get_remote_port_parent(
                   const struct device_node *node)
{
    struct device_node *np, *pp;

    /* Get remote endpoint node. */
    np = of_graph_get_remote_endpoint(node);

    pp = of_graph_get_port_parent(np);

    return pp;
}

/**
 * of_graph_get_remote_port() - get remote port node
 * @node: pointer to a local endpoint device_node
 *
 * Return: Remote port node associated with remote endpoint node linked
 *	   to @node. Use of_node_put() on it when done.
 */
struct device_node *of_graph_get_remote_port(const struct device_node *node)
{
    struct device_node *np;

    /* Get remote endpoint node. */
    np = of_graph_get_remote_endpoint(node);
    if (!np)
        return NULL;
    return of_get_next_parent(np);
}

int of_graph_get_endpoint_count(const struct device_node *np)
{
    struct device_node *endpoint;
    int num = 0;

    for_each_endpoint_of_node(np, endpoint)
        num++;

    return num;
}

/**
 * of_graph_get_remote_node() - get remote parent device_node for given port/endpoint
 * @node: pointer to parent device_node containing graph port/endpoint
 * @port: identifier (value of reg property) of the parent port node
 * @endpoint: identifier (value of reg property) of the endpoint node
 *
 * Return: Remote device node associated with remote endpoint node linked
 *	   to @node. Use of_node_put() on it when done.
 */
struct device_node *of_graph_get_remote_node(const struct device_node *node,
                         u32 port, u32 endpoint)
{
    struct device_node *endpoint_node, *remote;

    endpoint_node = of_graph_get_endpoint_by_regs(node, port, endpoint);
    if (!endpoint_node) {
        pr_debug("no valid endpoint (%d, %d) for node %pOF\n",
             port, endpoint, node);
        return NULL;
    }

    remote = of_graph_get_remote_port_parent(endpoint_node);
    if (!remote) {
        pr_debug("no valid remote node\n");
        return NULL;
    }

    if (!of_device_is_available(remote)) {
        pr_debug("not available for remote node\n");
        return NULL;
    }

    return remote;
}

static struct fwnode_handle *of_fwnode_get(struct fwnode_handle *fwnode)
{
    return of_fwnode_handle(to_of_node(fwnode));
}

static void of_fwnode_put(struct fwnode_handle *fwnode)
{
    to_of_node(fwnode);
}

static bool of_fwnode_device_is_available(const struct fwnode_handle *fwnode)
{
    return of_device_is_available(to_of_node(fwnode));
}

static bool of_fwnode_property_present(const struct fwnode_handle *fwnode,
                       const char *propname)
{
    return of_property_read_bool(to_of_node(fwnode), propname);
}

static int of_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
                         const char *propname,
                         unsigned int elem_size, void *val,
                         usize nval)
{
    const struct device_node *node = to_of_node(fwnode);

    if (!val)
        return of_property_count_elems_of_size(node, propname,
                               elem_size);

    switch (elem_size) {
    case sizeof(u8):
        return of_property_read_u8_array(node, propname, val, nval);
    case sizeof(u16):
        return of_property_read_u16_array(node, propname, val, nval);
    case sizeof(u32):
        return of_property_read_u32_array(node, propname, val, nval);
    case sizeof(u64):
        return of_property_read_u64_array(node, propname, val, nval);
    }

    return -ENXIO;
}

static int
of_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
                     const char *propname, const char **val,
                     usize nval)
{
    const struct device_node *node = to_of_node(fwnode);

    return val ?
        of_property_read_string_array(node, propname, val, nval) :
        of_property_count_strings(node, propname);
}


static struct fwnode_handle *
of_fwnode_get_parent(const struct fwnode_handle *fwnode)
{
    return of_fwnode_handle(of_get_parent(to_of_node(fwnode)));
}

static struct fwnode_handle *
of_fwnode_get_next_child_node(const struct fwnode_handle *fwnode,
                  struct fwnode_handle *child)
{
    return of_fwnode_handle(of_get_next_available_child(to_of_node(fwnode),
                                to_of_node(child)));
}

static struct fwnode_handle *
of_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
                   const char *childname)
{
    const struct device_node *node = to_of_node(fwnode);
    struct device_node *child;

    for_each_available_child_of_node(node, child)
        if (of_node_name_eq(child, childname))
            return of_fwnode_handle(child);

    return NULL;
}

static int
of_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
                 const char *prop, const char *nargs_prop,
                 unsigned int nargs, unsigned int index,
                 struct fwnode_reference_args *args)
{
    struct of_phandle_args of_args;
    int i;
    int ret;

    if (nargs_prop)
        ret = of_parse_phandle_with_args(to_of_node(fwnode), prop,
                         nargs_prop, index, &of_args);
    else
        ret = of_parse_phandle_with_fixed_args(to_of_node(fwnode), prop,
                               nargs, index, &of_args);
    if (ret < 0)
        return ret;
    if (!args)
        return 0;

    args->nargs = of_args.args_count;
    args->fwnode = of_fwnode_handle(of_args.np);

    for (i = 0; i < NR_FWNODE_REFERENCE_ARGS; i++)
        args->args[i] = i < of_args.args_count ? of_args.args[i] : 0;

    return 0;
}

static struct fwnode_handle *
of_fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
                  struct fwnode_handle *prev)
{
    return of_fwnode_handle(of_graph_get_next_endpoint(to_of_node(fwnode),
                               to_of_node(prev)));
}

static struct fwnode_handle *
of_fwnode_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
{
    return of_fwnode_handle(
        of_graph_get_remote_endpoint(to_of_node(fwnode)));
}

static struct fwnode_handle *
of_fwnode_graph_get_port_parent(struct fwnode_handle *fwnode)
{
    struct device_node *np;

    /* Get the parent of the port */
    np = of_get_parent(to_of_node(fwnode));
    if (!np)
        return NULL;

    /* Is this the "ports" node? If not, it's the port parent. */
    if (!of_node_name_eq(np, "ports"))
        return of_fwnode_handle(np);

    return of_fwnode_handle(of_get_next_parent(np));
}

static int of_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
                      struct fwnode_endpoint *endpoint)
{
    const struct device_node *node = to_of_node(fwnode);
    struct device_node *port_node = of_get_parent(node);

    endpoint->local_fwnode = fwnode;

    of_property_read_u32(port_node, "reg", &endpoint->port);
    of_property_read_u32(node, "reg", &endpoint->id);

    return 0;
}

const struct of_device_id *of_match_device_id(const struct of_device_id *matches,
                       const struct device_node *node)
{
    if ((!matches) || (!node))
        return NULL;
    return of_match_node(matches, node);
}

static const void *
of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
                const struct of_device_id *match, const struct device_node *node)
{
    return of_match_device_id(match, node);
}


const struct fwnode_operations of_fwnode_ops = {
    .get = of_fwnode_get,
    .put = of_fwnode_put,
    .device_is_available = of_fwnode_device_is_available,
    .device_get_match_data = of_fwnode_device_get_match_data,
    .property_present = of_fwnode_property_present,
    .property_read_int_array = of_fwnode_property_read_int_array,
    .property_read_string_array = of_fwnode_property_read_string_array,
    .get_parent = of_fwnode_get_parent,
    .get_next_child_node = of_fwnode_get_next_child_node,
    .get_named_child_node = of_fwnode_get_named_child_node,
    .get_reference_args = of_fwnode_get_reference_args,
    .graph_get_next_endpoint = of_fwnode_graph_get_next_endpoint,
    .graph_get_remote_endpoint = of_fwnode_graph_get_remote_endpoint,
    .graph_get_port_parent = of_fwnode_graph_get_port_parent,
    .graph_parse_endpoint = of_fwnode_graph_parse_endpoint,
};
